Opponents of a nearly $500 million bond for the Lone Star College system praised the electorate Sunday for voting down the measure, saying administrators failed to make a case for more buildings or more debt.

"They didn't explain their numbers fully, they didn't justify the cost, they didn't justify the need," said Kyle Scott, who opposed the bond and beat out an incumbent for a seat on the board of trustees. "It was just an excessive amount of debt that wasn't needed at this time."

Although the bond did not carry a tax rate increase, Scott said voters were wary of earlier tax increases and the prospect of rising property values increasing their taxes.

Officials with the system said they were disappointed the bond failed, and raised the spectre of capped enrollment at the open-enrollment system.

"We've added 30,000 students in five years," said Ray Laughter, vice chancellor for external affairs for the system. "Our early registration for this fall is up by double digits, and we don't expect it to slow down."

He said classroom sizes have increased 20 percent and more students are taking "hybrid" course that mix in-class hours with online coursework that can be done off campus.

"Our ultimate goal is to not cap enrollment," Laughter said. "Our goal is take in as many students as we can, and open the doors as best we can."

He noted that the total tax rate, which is the amount the district charges for bond debt combined with its annual rate for maintenance and operation, is the same as it was 15 years ago: about 12 cents per $100.

"It may go up one year and down the next, but over time it has stayed the same," Laughter said.

Although the tax rate fluctuates, it has gone up twice since the last bond election in 2008, to the dismay of conservative groups, like the tea party, that Scott credited with defeating the bond.

"The conservative groups in Montgomery County were very active," Scott said. "They rallied the troops."

The Texas Patriots PAC, a tea party group, wrote on its website: "We are not opposed to public entities use of bonds where the requirement is clearly needed. In our view ... there is way too much uncertainty surrounding the future enrollment levels at LSCS to support a half billion dollar expansion at this time."

The initiative failed by more than 2,000 votes out of almost 19,000 cast. In Harris County voters narrowly favored the bond issue, but 71 percent of votes cast in Montgomery County opposed the measure.

The community college district serves 90,000 students at six campuses through north Harris and Montgomery counties.

The $497.7 million bond was slated to improve and expand campuses and upgrade security, technology and other infrastructure.

Saturday's election also saw three incumbent trustees challenged.

Scott, who opposed the bond, defeated incumbent Tom Forestier and challenger Janie Branham for Position 2.

In his campaigning Trowbridge noted a Higher Education Coordinating Board report from January that projected that the college system's enrollment would only grow to 81,762 by 2020. "Until it puts forth a good faith effort to address all these fundamental issues behind their assumption of student growth, the college has not proven at all the need for a $500 million bond," a letter on his campaign website states.